Power transmission unit



Feb. 6, 1951 M. BITZER POWER TRANSMISSION UNIT Filed March 5, 1947 INVENTOR Mara/n B/Zzer ATTORNEYS Z i: V

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ifff'f; nepgsrArizs P TEN OFFICE rowan TRANSMISSION UNIT Martin Bitzcr, Kenmore, N. Y., assignor to Trico Products Corporation, Buffalo, N.- Y.

Application March 5, 1947, Serial No. 732,406

The inventionrelates'in general to power transmission units. I I "In the manufactureo'f automotive accessories; for example windshieldcleaners, by 'masspro- 'ducti'on,"it is very desirable that the bearing 'parts'be assembled with a minimum" effort and that-the assembly of the parts be accelerated and accomplished by a simplification of construction. The principal object of this invention has been to provide transmission means which may be easily and expeditiously manufactured, and

further to produce an improved and practical unit which embodies a minimum clearance between' the relative moving parts thereof to insure a better performance in use; *Another object has been to'provide sums ca p'able of having its componentpart secured tojgethr by a molding procedure "which affords economy in production.

"The above objects and advantages have been accomplished by the device shown in the accomp ying drawings, of which;

- ig. '1 shows a face view of a crank arm with -link-members connected thereto by means of the instant invention. portions thereof being broken away and omitted for clear'ness of illustration Fig. 2 is a side elevation of the crank, arm showingonly the transmission or connecting men sci the'inventionin such positions as to clearly illustrate them; v y f jFig. am an enlarged, sectional view of the as- 's'embled invention, taken on line III -III of Fig. l; v

Fig. 4 is an enlarged cross, sectional view ill lustrating a step in the method of manufacturing the transmission'unit; and v Fig. 5 is a greatlyenlargedfragmentary longitudinal sectional view taken through the shaft It is obvious that the herein described trans-'- mission unitjmay be used to connect any two coacting mechanical devices, although for illustrative purposes I have shown; the invention as applied to a vehicle windshield cleanerwherein thefdouble throw crank armfl8'isfixed to 'theflose cillato'ry power shafts of ar lwindshield cleaner motor and carries at its oppositeends the upstanding crank pins in the stub shafts H].

form of spindles or .5 Claims. (cram-2,),

A transmission unit is attached to each shaft 7 operation. to the crank arm 8 The sleeve member ll of the unit is secured to and formed upon the bearin surface l3 of the shaft member I 1] preferably by, being die cast thereon and may be formed with a laterally extending-bearing arm 14 that terminates in an upstanding retaining pin l5.

The shape of the spindle or shaft members! may be of any desired shape which, upon relative axial movement between the parts, will cause a slight spreading action of the bearing surface of the sleeve inorder to break the adhesion between the shaft and the sleeve, and further to provide slight clearance between the bearing surfaces of the coacting parts. This will insure a minimum clearance while affording free relative pivotal movement between the parts. For clearness of illustration, I have shown the bearing surface or portion l3 with a generally concave periphery, but it may have a hyper-boloid shape or other shape equivalent for the intended purpose and function.

The'concav'e surface l3 of the spindle may term nate at one end in a cylindrical portion I6 and at the opposite end in a similar cylindrical portion H. The shaft is extended beyond the collar I! in a head !8 which is separated from the collar by means of a groove 19. The outerside wall of the groove provides an inclined -surface 2B for purposes to be hereinafter described. 1 After the'sleeve'member II has been so molded about the bearing'portion of the shaft memher-the shank i2 is swaged or riveted in place upon the crank arm. A lubricant-bearing washer 2| may be initially placedabout the shank if desired. The'adb'esion be'tweenthe shaft and the encircling die cast sleeve is preferably broken at the timeof swaging th'eshank I 2. This is accomplished by supporting the'sleeve I I on the envu'zz, as depicted in Fig, 4, and then strik ing the shank a swafrzing' blow, suitable clearance being rovi e about the head I 8 'to avoid obstruction thereby.

When the shank I2 is struck,*the shaft will be forced downwardly into the sleeve and, being harder, will' serve to slightly expand such sleeve. This is'de pic'ted in the enlarged showing of Fig. 5; wherein-the-impactive action above described has driven the shaft downwardly within the sleeve to the double dot and'dash line 23 position. The full line 24 indicates the normal position assumed by the sleeve surface after the rebound, while the full line 25 represent the outer end of the sleeve inits initial surface contour. It will be noted that;; the surface l3. Fig. 4, In

shown in the position normally occupied and in which position it will have slight endwise movement and be free to pivot within the bearing member. A result of the axial displacement of the shaft during the adhesion breaking step is to slightly reshape the internal wall of the sleeve and form an annular bead or ridge 26 at the intersection of the surfaces 24 and 25, Fig. 5'. This ridge issfightly larger in diameter: than: the minimum diameter of the curved surface l3' of the shaft thu providing a minimum clearance space. The degree of clearance will be determined by the extent of axial movement. given. the shaft during the impactive action thereupon. Preferably the extent of axiaF movement is only sufficient to break the adhesion between the parts, whereby minimum clearance Willi be. had between the bearing surfaces. When the-bear ing sleeve is molded about the shaft member; it-

is preferable to coat the shaft member with graphite so asrto reduce the. molding adhesion between the parts and also. to make it easier: to break such: adhesi'om To provide for the easy and rapid assembly of the unit with connecting power transmitting linkage the link members 21 areprovided with openings to receive the: sleeves H and: within these opening may be arranged grommets 28; preferably of rubber, to: line the sleeve receiving openings ofthe links. order to confine the pivotal action of the link tothe bearing surfaces of the unit, and to prevent the rotation of the grommet: upon. the sleeve member of the unit upon. which it is mounted, there is provided an opening'or recess 29' each linkfor engagement with the retaining pin I'5= of the sleeve member, whereby the sleeve member will move inunison with the link member. The construction also prevents wear between the. grommet-and the bearing sleeve.

A retaining plate. 30f having a keyslotv 3! is en.-

gaged over'the head IQ of the shaft member, a

washer 32 being initially placed upon the adjacent cylindrical. portion; I? whereby to: limit lateral movement of the link. The retaining plates are extended toward each other and a: spring. 33 serves to keep them in. position. The outer ends of one of the link. members 21 may be connected to the windshield wiper arms, one being generally indicated at 34.

- While the riveting of the: shank L2 to the crank arm 8 is described as occurring. during; the adhesion. breaking step in the method of forming theunit, it is obvious that the.- swaging, operation could be performed separately.

-The" foregoing. detailed description has been made for ease in comprehending. the invention and: not by way'of limitation since the inventive principles involved arecapable. of being carried out in. other than the manner specifically set forth herein without departing. from the spirit of the invention and the scope of the appended 4 faces so shaped as to be held against axial separa tion, a link member connected to said sleeve member, said shaft member projecting beyond said sleeve member and formed with a grooved head, and retaining means carried by said head and engaging said link to preventaxial displacement thereof.

2. A transmission assembly comprising a unit having a unitary sleeve member, ashaft member rotatably carried by said sleeve member, said lmembers being formed with interengaging surfaces so shaped as to be held against axial separation, av link member having an opening receiving said sleeve member, said sleeve member having a pinfspaced from the sleeve axis and engaged with the link member to assure of. motion. therewith.

* A transmission assembly comprising a unit having aunitary sleeve member, a shaft member rotatably carried by said sleeve member, said members: being formed with interengagir-igv surfaces so shaped as to be held against axial. sepa ration, said sleeve member having an, upstanding arm-,, a bearingpin carried by said arm, and a link having an opening receiving the sleevev member and an adjacent recess for receiving saidpin, whereby said link and said sleeve member will be preventedfrom rotating. relatively toeach other.

.4. A transmission. assembly comprising a unit having a unitary sleeve member, a shaft member rotatably carried by said sleeve member, said members being formed with interengaging sur faces so shaped as to be held' against axial separation, said sleeve member. having anupstanding arm, a laterally extending bearing pin carried by said arm, a. link having an opening receiv ing. the sleeve member and an adjacent recess receiving said pin, whereby said link: and said sleeve; member will be prevented from rotating relativelyto. each. other, said shaft member having an end extending outwardly beyond said sleeve member and formed with a grooved head, and retaining means engaging said groove to re? tain said-link in place.

5. A transmission assembly comprising a unit having a unitary sleeve member, a shaft member rotatably carried. by said sleeve member, said members being formed with interengaging surfaces so shaped as to be held against axial separation, said sleeve member having a radially extending arm, a link having an opening receiving the sleeve member, and means connecting the radial arm to the link for movement in" unison whereby to. confine the rotatable action tothe sleeve. member upon the: shaft member.

7 MARTIN BITZEB...

REFERENCES CITED The following references are of record. in the.

file of this patent:

I UNITED STATES PATENTS Number Name Date 1,943,631. Skillman ,Jan.. 16, 1934 2,000,838 Gorton May 7,, 19.35 2,079,,113. Erlewine. s May 4,, 193? 2,289,103 Goerke. et a1. July. 14, 19.42

Certificate of Correction Patent No. 2,540,319 February '6, 1951 MARTIN BITZER It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4, lines 23 and 24:, for an upstanding arm, a bearing read a bearing arm, an upstanding; lines 35 and 36, for an upstanding arm, a laterally extending bearing read a laterally extending bearing arm, an apstanoling; 1 and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oifice.

Signed and sealed this 17th day of April, A. D. 1951.

THOMAS F. MURPHY,

Assistant Gammz'ssioner of Patents. 

